This invention relates generally to dispensing systems, and more particularly to a pump for dispensing condiments, beverages, and the like.
It is often desirable to dispense a condiment, a beverage, or the like by consistent amounts. Both mechanical and electronic devices have been used to control the portion dispensed with varying degrees of success. Some of the devices are rather complex and expensive. Some may be difficult to clean and maintain.
The present invention relates to a pump for dispensing beverages, condiments or the like. The pump includes a simple and reliable mechanism for providing consistent portion control in dispensing, and may be operated by hand. The pump includes a plunger movable in a chamber to activate an inlet check valve and an outlet check valve to fill the chamber with fluid from the inlet and dispense the fluid from the chamber through the outlet. The pump has a clean-in-place configuration that allows cleaning without disassembly by, for example, flowing a cleaning fluid through the pump. The pump desirably also includes a drawback feature at the outlet that prevents buildup at the dispensing outlet.
In accordance with an aspect of the present invention, a dispensing apparatus comprises a chamber including a cavity having an inlet and an outlet. An outlet check valve is disposed at the outlet of the chamber. The outlet check valve is openable to permit flow substantially only in a direction from the chamber cavity out through the outlet check valve. An inlet check valve is disposed at the inlet of the chamber. The inlet check valve is openable to permit flow substantially only in a direction through the inlet check valve into the chamber cavity. A plunger is disposed in the chamber. The plunger is movable from a first position to a second position away from the outlet and inlet check valves to open the inlet check valve and close the outlet check valve and draw fluid through the inlet check valve into the chamber cavity. The plunger is movable from the second position to the first position toward the outlet and inlet check valves to close the inlet check valve and open the outlet check valve and dispense fluid from the chamber cavity out through the outlet check valve.
In a preferred embodiment, the apparatus is self-contained, and is operable upon coupling to a BIB fluid source. The apparatus is easy to use and clean, and can be quickly adapted for dispensing another fluid by cleaning the pump channels and changing the BIB. No pump disassembly is required. The plunger may be coupled with a diaphragm which is attached to the chamber and extends across the chamber cavity. The diaphragm is movable in the chamber cavity by the plunger to open and close the inlet and outlet check valves. The diaphragm typically comprises a flexible elastomer.
In accordance with another aspect of the invention, a dispensing apparatus comprises a chamber including a cavity having an inlet and an outlet, an outlet valve disposed at the outlet of the chamber, and an inlet valve disposed at the inlet of the chamber. A plunger is disposed in the chamber. The plunger is movable from a first position to a second position away from the outlet and inlet valves to open the inlet valve and close the outlet valve and draw fluid through the inlet valve into the chamber cavity. The plunger is movable from the second position to the first position toward the outlet and inlet valves to close the inlet valve and open the outlet valve and dispense fluid from the chamber cavity out through the outlet valve. The outlet valve is configured to close in a delayed fashion when the plunger moves from the first position to the second position to allow a drawback flow from the outlet through the outlet valve into the chamber cavity for a preset period of time.
In accordance with another aspect of the invention, a method of dispensing a fluid comprises providing a chamber including a cavity having an inlet valve disposed at an inlet and an outlet valve disposed at an outlet. The chamber cavity is expanded to close the outlet valve and open the inlet valve to draw a fluid through the inlet valve into the chamber cavity. The chamber cavity is then contracted to close the inlet valve and open the outlet valve to dispense the fluid from the chamber cavity out through the outlet valve. Thereafter, the chamber cavity is expanded to close the outlet valve and open the inlet valve. The expansion of the chamber cavity produces a drop in pressure in the chamber cavity to draw a portion of the fluid back from the outlet through the outlet valve into the chamber cavity prior to closure of the outlet valve.